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-rw-r--r--gcc/ipa-modref.c198
-rw-r--r--gcc/ipa-modref.h20
-rw-r--r--gcc/tree-ssa-alias.c2
-rw-r--r--gcc/tree-ssa-structalias.c1
4 files changed, 187 insertions, 34 deletions
diff --git a/gcc/ipa-modref.c b/gcc/ipa-modref.c
index df4612b..d9d48cc 100644
--- a/gcc/ipa-modref.c
+++ b/gcc/ipa-modref.c
@@ -276,7 +276,8 @@ static GTY(()) fast_function_summary <modref_summary_lto *, va_gc>
modref_summary::modref_summary ()
: loads (NULL), stores (NULL), retslot_flags (0), static_chain_flags (0),
- writes_errno (false), side_effects (false), global_memory_read (false),
+ writes_errno (false), side_effects (false), nondeterministic (false),
+ calls_interposable (false), global_memory_read (false),
global_memory_written (false), try_dse (false)
{
}
@@ -332,13 +333,15 @@ modref_summary::useful_p (int ecf_flags, bool check_flags)
&& remove_useless_eaf_flags (static_chain_flags, ecf_flags, false))
return true;
if (ecf_flags & (ECF_CONST | ECF_NOVOPS))
- return (!side_effects && (ecf_flags & ECF_LOOPING_CONST_OR_PURE));
+ return ((!side_effects || !nondeterministic)
+ && (ecf_flags & ECF_LOOPING_CONST_OR_PURE));
if (loads && !loads->every_base)
return true;
else
kills.release ();
if (ecf_flags & ECF_PURE)
- return (!side_effects && (ecf_flags & ECF_LOOPING_CONST_OR_PURE));
+ return ((!side_effects || !nondeterministic)
+ && (ecf_flags & ECF_LOOPING_CONST_OR_PURE));
return stores && !stores->every_base;
}
@@ -357,8 +360,10 @@ struct GTY(()) modref_summary_lto
auto_vec<eaf_flags_t> GTY((skip)) arg_flags;
eaf_flags_t retslot_flags;
eaf_flags_t static_chain_flags;
- bool writes_errno;
- bool side_effects;
+ unsigned writes_errno : 1;
+ unsigned side_effects : 1;
+ unsigned nondeterministic : 1;
+ unsigned calls_interposable : 1;
modref_summary_lto ();
~modref_summary_lto ();
@@ -370,7 +375,8 @@ struct GTY(()) modref_summary_lto
modref_summary_lto::modref_summary_lto ()
: loads (NULL), stores (NULL), retslot_flags (0), static_chain_flags (0),
- writes_errno (false), side_effects (false)
+ writes_errno (false), side_effects (false), nondeterministic (false),
+ calls_interposable (false)
{
}
@@ -400,11 +406,13 @@ modref_summary_lto::useful_p (int ecf_flags, bool check_flags)
&& remove_useless_eaf_flags (static_chain_flags, ecf_flags, false))
return true;
if (ecf_flags & (ECF_CONST | ECF_NOVOPS))
- return (!side_effects && (ecf_flags & ECF_LOOPING_CONST_OR_PURE));
+ return ((!side_effects || !nondeterministic)
+ && (ecf_flags & ECF_LOOPING_CONST_OR_PURE));
if (loads && !loads->every_base)
return true;
if (ecf_flags & ECF_PURE)
- return (!side_effects && (ecf_flags & ECF_LOOPING_CONST_OR_PURE));
+ return ((!side_effects || !nondeterministic)
+ && (ecf_flags & ECF_LOOPING_CONST_OR_PURE));
return stores && !stores->every_base;
}
@@ -586,6 +594,10 @@ modref_summary::dump (FILE *out)
fprintf (out, " Writes errno\n");
if (side_effects)
fprintf (out, " Side effects\n");
+ if (nondeterministic)
+ fprintf (out, " Nondeterministic\n");
+ if (calls_interposable)
+ fprintf (out, " Calls interposable\n");
if (global_memory_read)
fprintf (out, " Global memory read\n");
if (global_memory_written)
@@ -626,6 +638,10 @@ modref_summary_lto::dump (FILE *out)
fprintf (out, " Writes errno\n");
if (side_effects)
fprintf (out, " Side effects\n");
+ if (nondeterministic)
+ fprintf (out, " Nondeterministic\n");
+ if (calls_interposable)
+ fprintf (out, " Calls interposable\n");
if (arg_flags.length ())
{
for (unsigned int i = 0; i < arg_flags.length (); i++)
@@ -869,6 +885,20 @@ record_access_p (tree expr)
return true;
}
+/* Return true if ECF flags says that nondeterminsm can be ignored. */
+
+static bool
+ignore_nondeterminism_p (tree caller, int flags)
+{
+ if ((flags & (ECF_CONST | ECF_PURE))
+ && !(flags & ECF_LOOPING_CONST_OR_PURE))
+ return true;
+ if ((flags & (ECF_NORETURN | ECF_NOTHROW)) == (ECF_NORETURN | ECF_NOTHROW)
+ || (!opt_for_fn (caller, flag_exceptions) && (flags & ECF_NORETURN)))
+ return true;
+ return false;
+}
+
/* Return true if ECF flags says that return value can be ignored. */
static bool
@@ -953,17 +983,37 @@ merge_call_side_effects (modref_summary *cur_summary,
&& !(flags & ECF_LOOPING_CONST_OR_PURE))
return changed;
- if (!cur_summary->side_effects && callee_summary->side_effects)
+ if (!(flags & (ECF_CONST | ECF_NOVOPS | ECF_PURE))
+ || (flags & ECF_LOOPING_CONST_OR_PURE))
{
- if (dump_file)
- fprintf (dump_file, " - merging side effects.\n");
- cur_summary->side_effects = true;
- changed = true;
- }
+ if (!cur_summary->side_effects && callee_summary->side_effects)
+ {
+ if (dump_file)
+ fprintf (dump_file, " - merging side effects.\n");
+ cur_summary->side_effects = true;
+ changed = true;
+ }
+ if (!cur_summary->nondeterministic && callee_summary->nondeterministic
+ && !ignore_nondeterminism_p (current_function_decl, flags))
+ {
+ if (dump_file)
+ fprintf (dump_file, " - merging nondeterministic.\n");
+ cur_summary->nondeterministic = true;
+ changed = true;
+ }
+ }
if (flags & (ECF_CONST | ECF_NOVOPS))
return changed;
+ if (!cur_summary->calls_interposable && callee_summary->calls_interposable)
+ {
+ if (dump_file)
+ fprintf (dump_file, " - merging calls interposable.\n");
+ cur_summary->calls_interposable = true;
+ changed = true;
+ }
+
if (always_executed
&& callee_summary->kills.length ()
&& (!cfun->can_throw_non_call_exceptions
@@ -1000,11 +1050,13 @@ merge_call_side_effects (modref_summary *cur_summary,
not always bind to current def: it is possible that memory load
was optimized out earlier which may not happen in the interposed
variant. */
- if (!callee_node->binds_to_current_def_p ())
+ if (!callee_node->binds_to_current_def_p ()
+ && !cur_summary->calls_interposable)
{
if (dump_file)
- fprintf (dump_file, " - May be interposed: collapsing loads.\n");
- cur_summary->loads->collapse ();
+ fprintf (dump_file, " - May be interposed.\n");
+ cur_summary->calls_interposable = true;
+ changed = true;
}
if (dump_file)
@@ -1161,9 +1213,17 @@ process_fnspec (modref_summary *cur_summary,
&& stmt_could_throw_p (cfun, call)))
{
if (cur_summary)
- cur_summary->side_effects = true;
+ {
+ cur_summary->side_effects = true;
+ if (!ignore_nondeterminism_p (current_function_decl, flags))
+ cur_summary->nondeterministic = true;
+ }
if (cur_summary_lto)
- cur_summary_lto->side_effects = true;
+ {
+ cur_summary_lto->side_effects = true;
+ if (!ignore_nondeterminism_p (current_function_decl, flags))
+ cur_summary_lto->nondeterministic = true;
+ }
}
if (flags & (ECF_CONST | ECF_NOVOPS))
return true;
@@ -1388,9 +1448,9 @@ analyze_load (gimple *, tree, tree op, void *data)
if (dump_file)
fprintf (dump_file, " (volatile or can throw; marking side effects) ");
if (summary)
- summary->side_effects = true;
+ summary->side_effects = summary->nondeterministic = true;
if (summary_lto)
- summary_lto->side_effects = true;
+ summary_lto->side_effects = summary_lto->nondeterministic = true;
}
if (!record_access_p (op))
@@ -1429,9 +1489,9 @@ analyze_store (gimple *stmt, tree, tree op, void *data)
if (dump_file)
fprintf (dump_file, " (volatile or can throw; marking side effects) ");
if (summary)
- summary->side_effects = true;
+ summary->side_effects = summary->nondeterministic = true;
if (summary_lto)
- summary_lto->side_effects = true;
+ summary_lto->side_effects = summary_lto->nondeterministic = true;
}
if (!record_access_p (op))
@@ -1497,9 +1557,15 @@ analyze_stmt (modref_summary *summary, modref_summary_lto *summary_lto,
switch (gimple_code (stmt))
{
case GIMPLE_ASM:
- if (gimple_asm_volatile_p (as_a <gasm *> (stmt))
- || (cfun->can_throw_non_call_exceptions
- && stmt_could_throw_p (cfun, stmt)))
+ if (gimple_asm_volatile_p (as_a <gasm *> (stmt)))
+ {
+ if (summary)
+ summary->side_effects = summary->nondeterministic = true;
+ if (summary_lto)
+ summary_lto->side_effects = summary_lto->nondeterministic = true;
+ }
+ if (cfun->can_throw_non_call_exceptions
+ && stmt_could_throw_p (cfun, stmt))
{
if (summary)
summary->side_effects = true;
@@ -2826,6 +2892,8 @@ analyze_function (function *f, bool ipa)
param_modref_max_accesses);
summary->writes_errno = false;
summary->side_effects = false;
+ summary->nondeterministic = false;
+ summary->calls_interposable = false;
}
if (lto)
{
@@ -2841,6 +2909,8 @@ analyze_function (function *f, bool ipa)
param_modref_max_accesses);
summary_lto->writes_errno = false;
summary_lto->side_effects = false;
+ summary_lto->nondeterministic = false;
+ summary_lto->calls_interposable = false;
}
analyze_parms (summary, summary_lto, ipa,
@@ -2913,9 +2983,10 @@ analyze_function (function *f, bool ipa)
if (!ipa && flag_ipa_pure_const)
{
if (!summary->stores->every_base && !summary->stores->bases
- && !summary->side_effects)
+ && !summary->nondeterministic)
{
- if (!summary->loads->every_base && !summary->loads->bases)
+ if (!summary->loads->every_base && !summary->loads->bases
+ && !summary->calls_interposable)
fixup_cfg = ipa_make_function_const
(cgraph_node::get (current_function_decl),
summary->side_effects, true);
@@ -3149,6 +3220,8 @@ modref_summaries::duplicate (cgraph_node *, cgraph_node *dst,
dst_data->kills.splice (src_data->kills);
dst_data->writes_errno = src_data->writes_errno;
dst_data->side_effects = src_data->side_effects;
+ dst_data->nondeterministic = src_data->nondeterministic;
+ dst_data->calls_interposable = src_data->calls_interposable;
if (src_data->arg_flags.length ())
dst_data->arg_flags = src_data->arg_flags.copy ();
dst_data->retslot_flags = src_data->retslot_flags;
@@ -3177,6 +3250,8 @@ modref_summaries_lto::duplicate (cgraph_node *, cgraph_node *,
dst_data->loads->copy_from (src_data->loads);
dst_data->writes_errno = src_data->writes_errno;
dst_data->side_effects = src_data->side_effects;
+ dst_data->nondeterministic = src_data->nondeterministic;
+ dst_data->calls_interposable = src_data->calls_interposable;
if (src_data->arg_flags.length ())
dst_data->arg_flags = src_data->arg_flags.copy ();
dst_data->retslot_flags = src_data->retslot_flags;
@@ -3506,6 +3581,8 @@ modref_write ()
struct bitpack_d bp = bitpack_create (ob->main_stream);
bp_pack_value (&bp, r->writes_errno, 1);
bp_pack_value (&bp, r->side_effects, 1);
+ bp_pack_value (&bp, r->nondeterministic, 1);
+ bp_pack_value (&bp, r->calls_interposable, 1);
if (!flag_wpa)
{
for (cgraph_edge *e = cnode->indirect_calls;
@@ -3578,11 +3655,15 @@ read_section (struct lto_file_decl_data *file_data, const char *data,
{
modref_sum->writes_errno = false;
modref_sum->side_effects = false;
+ modref_sum->nondeterministic = false;
+ modref_sum->calls_interposable = false;
}
if (modref_sum_lto)
{
modref_sum_lto->writes_errno = false;
modref_sum_lto->side_effects = false;
+ modref_sum_lto->nondeterministic = false;
+ modref_sum_lto->calls_interposable = false;
}
gcc_assert (!modref_sum || (!modref_sum->loads
@@ -3635,6 +3716,20 @@ read_section (struct lto_file_decl_data *file_data, const char *data,
if (modref_sum_lto)
modref_sum_lto->side_effects = true;
}
+ if (bp_unpack_value (&bp, 1))
+ {
+ if (modref_sum)
+ modref_sum->nondeterministic = true;
+ if (modref_sum_lto)
+ modref_sum_lto->nondeterministic = true;
+ }
+ if (bp_unpack_value (&bp, 1))
+ {
+ if (modref_sum)
+ modref_sum->calls_interposable = true;
+ if (modref_sum_lto)
+ modref_sum_lto->calls_interposable = true;
+ }
if (!flag_ltrans)
{
for (cgraph_edge *e = node->indirect_calls; e; e = e->next_callee)
@@ -4162,6 +4257,18 @@ propagate_unknown_call (cgraph_node *node,
cur_summary_lto->side_effects = true;
changed = true;
}
+ if (cur_summary && !cur_summary->nondeterministic
+ && !ignore_nondeterminism_p (node->decl, ecf_flags))
+ {
+ cur_summary->nondeterministic = true;
+ changed = true;
+ }
+ if (cur_summary_lto && !cur_summary_lto->nondeterministic
+ && !ignore_nondeterminism_p (node->decl, ecf_flags))
+ {
+ cur_summary_lto->nondeterministic = true;
+ changed = true;
+ }
}
if (ecf_flags & (ECF_CONST | ECF_NOVOPS))
return changed;
@@ -4421,6 +4528,20 @@ modref_propagate_in_scc (cgraph_node *component_node)
cur_summary_lto->side_effects = true;
changed = true;
}
+ if (callee_summary && !cur_summary->nondeterministic
+ && callee_summary->nondeterministic
+ && !ignore_nondeterminism_p (cur->decl, flags))
+ {
+ cur_summary->nondeterministic = true;
+ changed = true;
+ }
+ if (callee_summary_lto && !cur_summary_lto->nondeterministic
+ && callee_summary_lto->nondeterministic
+ && !ignore_nondeterminism_p (cur->decl, flags))
+ {
+ cur_summary_lto->nondeterministic = true;
+ changed = true;
+ }
if (flags & (ECF_CONST | ECF_NOVOPS))
continue;
@@ -4430,7 +4551,16 @@ modref_propagate_in_scc (cgraph_node *component_node)
the interposed variant. */
if (!callee_edge->binds_to_current_def_p ())
{
- changed |= collapse_loads (cur_summary, cur_summary_lto);
+ if (cur_summary && !cur_summary->calls_interposable)
+ {
+ cur_summary->calls_interposable = true;
+ changed = true;
+ }
+ if (cur_summary_lto && !cur_summary_lto->calls_interposable)
+ {
+ cur_summary_lto->calls_interposable = true;
+ changed = true;
+ }
if (dump_file)
fprintf (dump_file, " May not bind local;"
" collapsing loads\n");
@@ -4516,9 +4646,10 @@ modref_propagate_in_scc (cgraph_node *component_node)
? summaries_lto->get (cur)
: NULL;
if (summary && !summary->stores->every_base && !summary->stores->bases
- && !summary->side_effects)
+ && !summary->nondeterministic)
{
- if (!summary->loads->every_base && !summary->loads->bases)
+ if (!summary->loads->every_base && !summary->loads->bases
+ && !summary->calls_interposable)
pureconst |= ipa_make_function_const
(cur, summary->side_effects, false);
else
@@ -4526,9 +4657,10 @@ modref_propagate_in_scc (cgraph_node *component_node)
(cur, summary->side_effects, false);
}
if (summary_lto && !summary_lto->stores->every_base
- && !summary_lto->stores->bases && !summary_lto->side_effects)
+ && !summary_lto->stores->bases && !summary_lto->nondeterministic)
{
- if (!summary_lto->loads->every_base && !summary_lto->loads->bases)
+ if (!summary_lto->loads->every_base && !summary_lto->loads->bases
+ && !summary_lto->calls_interposable)
pureconst |= ipa_make_function_const
(cur, summary_lto->side_effects, false);
else
diff --git a/gcc/ipa-modref.h b/gcc/ipa-modref.h
index 9e8a30fd..4eb696d 100644
--- a/gcc/ipa-modref.h
+++ b/gcc/ipa-modref.h
@@ -32,11 +32,31 @@ struct GTY(()) modref_summary
modref_records *stores;
auto_vec<modref_access_node> GTY((skip)) kills;
auto_vec<eaf_flags_t> GTY((skip)) arg_flags;
+
eaf_flags_t retslot_flags;
eaf_flags_t static_chain_flags;
+
unsigned writes_errno : 1;
+ /* Side effects does not include memory loads and stores which are
+ expressed using loads, stores and calls_interposable fields. */
unsigned side_effects : 1;
+ /* If true function can not be CSE optimized because it may behave
+ differently even if invoked with same inputs. */
+ unsigned nondeterministic : 1;
+ /* IF true the function may read any reachable memory but not use
+ it for anything useful. This may happen i.e. when interposing
+ function with optimized out conditional with unoptimized one.
+
+ In this situation the loads summary is not useful for DSE but
+ it is still useful for CSE. */
+ unsigned calls_interposable : 1;
+
/* Flags coputed by finalize method. */
+
+ /* global_memory_read is not set for functions calling functions
+ with !binds_to_current_def which, after interposition, may read global
+ memory but do nothing useful with it (except for crashing if some
+ stores are optimized out. */
unsigned global_memory_read : 1;
unsigned global_memory_written : 1;
unsigned try_dse : 1;
diff --git a/gcc/tree-ssa-alias.c b/gcc/tree-ssa-alias.c
index 093d65c..02bbc87 100644
--- a/gcc/tree-ssa-alias.c
+++ b/gcc/tree-ssa-alias.c
@@ -2765,7 +2765,7 @@ ref_maybe_used_by_call_p_1 (gcall *call, ao_ref *ref, bool tbaa_p)
if (node && node->binds_to_current_def_p ())
{
modref_summary *summary = get_modref_function_summary (node);
- if (summary)
+ if (summary && !summary->calls_interposable)
{
if (!modref_may_conflict (call, summary->loads, ref, tbaa_p))
{
diff --git a/gcc/tree-ssa-structalias.c b/gcc/tree-ssa-structalias.c
index 6141e94..06eb22c 100644
--- a/gcc/tree-ssa-structalias.c
+++ b/gcc/tree-ssa-structalias.c
@@ -4266,6 +4266,7 @@ determine_global_memory_access (gcall *stmt,
if (reads_global_memory && *reads_global_memory)
*reads_global_memory = summary->global_memory_read;
if (reads_global_memory && uses_global_memory
+ && !summary->calls_interposable
&& !*reads_global_memory && node->binds_to_current_def_p ())
*uses_global_memory = false;
}
generated by cgit v1.1 at 2025-06-03 14:45:11 +0000